102 NEW YORK STATE MUSEUM 



While we are well aware that none of these structural features 

 is fully decisive of the aptychus nature as against the crustacean 

 nature of the valves, they are nevertheless of considerable sig- 

 nificance if added to the facts that none of the valves of the genera 

 of the Discinocarina has as yet been found with an abdomen of a 

 crustacean and that they all have a shape which is clearly sugges- 

 tive of an aptychus. If one of the main arguments against their 

 reference to the cephalopods as aptychi was that no true aptychi 

 have been found in the Paleozoic formations then this argument 

 would be much weakened by the probability that the Paleozoic 

 cephalopods had only cartilaginous aptychi or at the best cartilagin- 

 ous aptychi with a thin conchiolinous inner layer, the anaptychus. 

 These cartilaginous plates, for the attachment of the detractor 

 muscles of the funnel, would naturally also have existed in the 

 Ordovician and Silurian cephalopods and thus account for those 

 earlier anaptychi considered as Discinocarina. 



Anatifopsis wardelli nov. 



Plate 32, figures 1-12 



Mr H. C. Wardell, while collecting the Otisville eurypterid 

 material described in New York State Museum Memoir 14, also 

 secured in a bed of greenish shaly sandstone above the eurypterid- 

 bearing strata, about a drawerfull of specimens of a new crustacean. 

 Preparation of this material has brought out the interesting fact 

 that it is an American representative of the cirriped genus Ana- 

 tifopsis of Barrande. The genus as described by Barrande 1 contains 

 four species and is based on detached valves which are somewhat 

 quadrilateral in shape. The main generic character is seen by 

 Barrande in the fact that the plates have the lower part of the 

 base marked out into one or two horizontal segments which are 

 more or less separated from the body of the valve. He also con- 

 siders as a constant and typical character the fine regular, longi- 

 tudinal striation of the valves. Our material shows both the char- 

 acteristic shape of the valves of Anatifopsis with the marked-off 

 basal segments (see pi. 32, figs. 1, 2, 5, 6) as also the typical 

 longitudinal striation. As in all cirripeds, the form of the valves 

 is quite variable according to their place in the capitulum or 

 peduncle. This is markedly the case in both the Bohemian and 



1 J. Barrande. Syst. Sil. du Centre d'e la Boheme, Supplement au v. 1, 

 P. 577- 1872. 



